Why You Should Regularly Check Your Dog For Canine Heartworm

Thinking of visiting the vet for a checkup? Remember to get a screening for canine heartworm. Heartworm is a debilitating, parasitic disease that affects our furry friends. If left untreated, canine heartworm can be fatal. 

Heartworm disease affects cats and dogs all over the United States and leaves lasting effects, even after the treatment is over. Heartworms can grow up to 12 inches long and breed inside our pets, causing damage to multiple organs in their bodies. 

The only way to beat heartworm is to make sure you take preventative steps in the form of regular checkups and medicine. It’s incredibly easy to prevent, but very difficult to diagnose and cure. 

In this article, we’ll outline everything you need to know about canine heartworm, heartworm treatment for dogs, heartworm prevention for dogs, and heartworm symptoms in dogs. 

What Is Heartworm?

Heartworm is a parasitic disease that can spread to dogs through the bite of a mosquito. The worm is called Dirofilaria immitis, and our dogs can serve as hosts. The mosquito carries the parasite larvae in its system and transfers it to the dog with a bite. 

These heartworms can mate, breed, and grow up to a foot inside the dog’s arteries and veins. Dogs can carry several hundreds of these worms if left untreated. 

The worms can occupy vital blood vessels in a dog and can cause severe damage and inflammation to the heart, lungs, and other organs. 

Causes Of Heartworm

So, how do dogs get heartworms? There is only one known cause of heartworm disease: a bite from a mosquito carrying the parasitic larvae. This is not a contagious disease, so an infected dog cannot transmit heartworm to a healthy dog. 

The infective larvae travel through the dog’s bloodstream. From there, its life cycle begins. After 6 to 7 months from the bite, the worms mature into adults inside the dog. 

Adult heartworms look like cooked spaghetti. Male worms grow to 4 to 6 inches long while female worms grow up to 12 inches. Once grown, they breed and release their offspring into the major blood vessels of the dog and finish their life cycle

Signs And Symptoms

In the early stages, your dog might not show symptoms of infestation. As time passes and the worms grow, more symptoms begin to manifest. 

Here are a few telltale signs to look out for if you suspect your pup might have heartworm disease:

Fatigue And Lethargy

If your dog displays exhaustion even after moderate exercise or loses interest in activities like playing and going for walks, they might have heartworm. 

Mild Cough

A dry and persistent cough is another sign that your pup might have heartworm. If your dog is otherwise healthy and doesn’t have a cold, then a dry cough is a warning sign. 

Decreased Appetite

The growth of worms inside causes a drop in your dog’s appetite. You may not notice it immediately but as the months pass, your dog’s lack of appetite will become more apparent.

Unexplained Weight Loss

Since the dog isn’t eating as much as it should, there can be weight loss. Diseases of a parasitic nature also cause a lot of weight loss as worms feed on the host. 

Swollen Belly

Excess fluid in the abdomen caused by heart failure makes the dog’s belly swell up with fluid. 

Labored Breathing

In the late stages of the disease, you might notice that your dog has difficulty breathing. Worms can grow and cause blockages in the heart leading to heart failure, caval syndrome, and collapsing arteries. 

This causes respiratory issues, pale gums, and sometimes bloody or coffee-colored urine. 

Regular Checkups

The best way to stop these symptoms from happening is to prevent the disease in the first place. Remember, heartworm prevention is much easier than curing it.

Go for regular check-ups and ensure that you take preventative medicine. Its preventative medicine often comes in a chewable pill that must be taken each month. Skipping a dose for even one month can put your dog at risk. It is highly effective in preventing parasitic growth in dogs. 

Getting Tested for Heartworms

Two tests can detect the presence of heartworms in dogs: an antigen test and a test for picking up microfilariae in their bloodstream. 

An antigen test detects proteins or antigens from the adult female heartworm in the bloodstream. The catch is that this test can only detect heartworms after they have matured inside the dog, which could mean that you have to wait at least five months after the mosquito bite.

The other test detects microfilariae in the dog. Microfilariae are millions of microscopic worms. They are the offspring produced by adult heartworms. Again, this test only diagnoses heartworms after they’ve matured and mated, which could be six or seven months after the bite. 

In both cases, its diagnosis comes very late. 


Ironically, the best treatment is heartworm prevention for dogs. It is very easy to avoid being bitten. Being aware of the disease and taking preventative measures can save your dog’s life. 

Avoid humid, damp places where there are mosquitoes present. Go to the vet regularly and get an antigen test every 12 months even if your dog looks healthy. 

In terms of treatment, a series of injectable drugs are administered to kill heartworms in the heart and blood vessels. It’s crucial to note that even after successful dog heartworm treatment, there can still be complications or a reduced quality of life for your pup.

In severe cases when the worms multiply rapidly and cause blockages in the heart vessels, surgeries need to be performed. Without the surgery, such cases can become life-threatening. 

How long can a dog live with heartworms? Dog life expectancy after heartworm treatment can significantly be shorter depending on how severe the infestation was. Sometimes, it can take away 6 years from a dog’s lifespan. 

Post-treatment, appropriate measures need to be taken to ensure that there is no relapse or reinfection.

Conclusion: Heartworm Is Fatal But Easily Preventable 

Heartworm is a scary and fatal infestation but with a little effort and some heartworm medication for dogs, you don’t need to worry about losing your dog to this disease. 

We hope this article helped you learn more about canine heartworm disease. If you haven’t done so yet, get your dog tested for it and get preventative heartworm medicine

Leave a comment

Please note, comments must be approved before they are published

Best Selling Combo

Best Selling Combo

Heartgard Nexgard Combo for Dogs Flea, Ticks & Heartworm Treatment